This invention relates to opaque projectors of images upon a suitable screen from photographs, post cards, pages and three-dimensional objects.
More particularly, it relates to a method of projecting images and their color clearly by the use of greater light intensity and increased lens effectiveness in conjunction with increased cooling effectiveness.
Early image projectors such as described in U.S. Pat. Nos. 1,424,847, 1,848,378 and 2,047,002 were void of cooling methods. Objects being projected tended to distort with heat or to ignite if held under projector light long enough for the purpose intended in most cases. Later projectors provided methods of dissipating heat such as described in U.S. Pat. Nos. 2,661,655, 3,117,489 and 3,224,321. Still other patents provided improved methods for holding opaque objects, such as described in U.S. Pat. Nos. 2,449,112 and 2,578,106.
None of the prior art in previous patents or in known use provide sufficient cooling to allow for high intensity and duration of light in combination with high magnification of light and images being projected. A method of cooling described in U.S. Patent No. 2,661,655 provided for cooling through porous or foraminous platen devices. But it did not allow for flexibility of holding devices. A cooling-air circulation method described in U.S. Pat. No. 3,117,489 provided for circulating air first over the light source and then over the platten and the objects thereon with an effect of heating further the objects being projected. U.S. Pat. No. 3,224,321 provided for suction of heated air from the projector, rather than forcing entry of air for cooling.
Also, heretofore, in order to project scenes from photographs onto a wall, it was necessary to have slides made so they could be placed in a projector for projection onto a screen. Direct projection from photographs was infeasible.
Thus, there is a need for an image projector that provides sufficient heat elimination to enable photographs and other delicate objects to be placed in magnified light so that a clear image of same can be projected onto a wall or screen.